What happened
On July 14, 2011, a Schempp Hirth Janus B glider, registration F-CEPS, was returning from a local flight near Jouy-sur-Morin. During the flight, which had lasted approximately 3 hours and 50 minutes, the instructor and student encountered deteriorating weather conditions. While flying at an altitude of roughly 360 meters, the crew realized that a headwind prevented them from reaching the Coulommiers aerodrome.
As the instructor attempted to divert to the La Ferté-Gaucher aerodrome, the aircraft entered a steady descent of 3 to 4 meters per second. Unable to arrest the descent, the instructor decided to perform a forced landing in a nearby field. After searching for a suitable site, the crew identified a harvested wheat field.
During the final approach, the instructor identified electrical lines and trees ahead, as well as a tailwind. In response, the instructor executed a sharp 90-degree turn to land in an adjacent wheat field. Despite deploying full airbrakes, the aircraft landed long, approximately 80 meters from the end of the field. As the glider reached the edge of the field, the crew noticed tall grass. The instructor attempted a ground loop to avoid the vegetation, but the glider crossed a road and struck an embankment bordering a cornfield, causing the aircraft to come to a halt.
The investigation
The investigation focused on the decision-making process regarding the diversion and the selection of the landing site. Investigators examined the aircraft's flight path, the meteorological conditions, and the visibility constraints faced by the crew. The investigation also reviewed the pilot's manual, which specifies that decisions for forced landings should be made before the aircraft descends below 400 meters.
Findings
- The primary cause of the accident was the inappropriate selection of the landing field.
- The instructor identified obstacles at the end of the chosen field too late, prompting a sudden change in landing strategy.
- The instructor's position in the rear seat limited his ability to effectively scan for obstacles.
- The decision to land in the second field resulted in a long landing that placed the aircraft in close proximity to unidentified hazards.
- A more timely decision to terminate the flight would have provided sufficient altitude to properly scout the landing area.